Meander line capacitively-loaded magnetic dipole antenna

Abstract

A meander line capacitively-loaded magnetic dipole antenna is disclosed. The antenna includes a transformer loop having a balanced feed interface, and a meander line capacitively-loaded magnetic dipole radiator. The meander line capacitively-loaded magnetic dipole radiator also includes an electric field bridge. For example, the meander line capacitively-loaded magnetic dipole radiator may include a quasi loop with a first end and a second end, with the electric field bridge interposed between the quasi loop first and second ends. The electric field bridge may be an element such as a dielectric gap, lumped element, circuit board surface-mounted, ferroelectric tunable, or a microelectromechanical system (MEMS) capacitor. The transformer loop has a radiator interface coupled to a quasi loop transformer interface. In one aspect, the coupled interfaces are a shared perimeter portion shared by both loops.

1. A meander line capacitively-loaded magnetic dipole antenna, the antenna comprising:
 a transformer loop having a balanced feed interface; and, 
 a meander line capacitively-loaded magnetic dipole radiator connected to the transformer loop and comprising a first group of substantially parallel meander lines and a second group of substantially parallel meander lines. 
 
   
   
     2. The antenna of  claim 1  wherein the meander line capacitively-loaded magnetic dipole radiator comprises an electric field bridge. 
   
   
     3. The antenna of  claim 2  wherein the meander line capacitively-loaded magnetic dipole radiator comprises a quasi loop with a first end and a second end, the quasi loop comprising the first group of substantially parallel meander lines and,
 the second group of substantially parallel meander lines. 
 
   
   
     4. The antenna of  claim 3  wherein the electric field bridge is interposed between the quasi loop first and second ends. 
   
   
     5. The antenna of  claim 3  wherein the electric field bridge is an element selected from the group consisting of a dielectric gap, lumped element, circuit board surface-mounted, ferroelectric tunable, and a microelectromechanical system (MEMS) capacitor. 
   
   
     6. The antenna of  claim 3  wherein the electric field bridge is a dielectric gap capacitor with a first end section about parallel to a second end section. 
   
   
     7. The antenna of  claim 4  wherein the transformer loop has a radiator interface; and,
 wherein the quasi loop has a transformer interface coupled to the transformer loop radiator interface. 
 
   
   
     8. The antenna of  claim 7  wherein the transformer loop has a first side; and,
 wherein the quasi loop has a perimeter that shares the first side with the transformer loop. 
 
   
   
     9. The antenna of  claim 8  wherein the transformer loop first side has a first end and second end;
 wherein the electric field bridge has a first end and a second end; 
 wherein the first group of substantially parallel lines is connected to the first end of the first side and the second group of substantially parallel lines is about orthogonal to the first group of lines and interposed between the first group of lines and the bridge first end; and, 
 wherein the quasi loop comprises a third group of substantially parallel lines connected to the second end of the first side, and a fourth group of substantially parallel lines, about orthogonal to the third group of lines, interposed between the third group of lines and the bridge second end. 
 
   
   
     10. The antenna of  claim 9  wherein the quasi loop third group of lines is about parallel to the first group of lines, and the fourth group of lines is about parallel to the second group of lines. 
   
   
     11. The antenna of  claim 9  wherein the meander line capacitively-loaded magnetic dipole radiator resonates at a first frequency and at a second frequency, non-harmonically related to the first frequency. 
   
   
     12. The antenna of  claim 4  wherein the quasi loop first group of lines are non-coplanar with the second group of lines. 
   
   
     13. The antenna of  claim 1  wherein the first group of meander lines is about orthogonal to the second group of meander lines. 
   
   
     14. The antenna of  claim 1  wherein the transformer loop and the meander line capacitively-loaded magnetic dipole radiator are coplanar. 
   
   
     15. The antenna of  claim 1  wherein the transformer loop and the meander line capacitively-loaded magnetic dipole radiator are non-coplanar. 
   
   
     16. The antenna of  claim 1  further comprising:
 a sheet of dielectric material with a surface; and, 
 wherein the transformer loop and capacitively-loaded magnetic dipole quasi loop are metal conductive traces formed overlying the surface of the dielectric sheet. 
 
   
   
     17. The antenna of  claim 16  wherein the dielectric sheet is a material selected from the group comprising paper, polyester, polyimide, synthetic aromatic polyamide polymer, phenolic, polytetrafluoroethylene (PTFE), chlorosulfonated polyethylene, silicon, and ethylene propylene diene monomer (EPDM). 
   
   
     18. A wireless telephone communications device capacitively-loaded magnetic dipole antenna, the device comprising:
 a housing; 
 a telephone transceiver embedded in the housing; and,
 a balanced teed meander line capacitively-loaded magnetic dipole antenna embedded in the housing, the antenna comprising: 
 a transformer loop having a balanced feed interface; and
 a meander line capacitively-loaded magnetic dipole radiator connected to the transformer loop and comprising a first group of substantially parallel meander lines and a second group of substantially parallel meander lines. 
 
 
 
   
   
     19. The device of  claim 18  wherein the capacitively-loaded magnetic dipole antenna has a radiation efficiency that is insensitive to the proximity of the placement of a user's hand on the housing. 
   
   
     20. The device of  claim 18  wherein the housing is a two-part configuration selected from the group consisting of a flip, slider, and swivel cellular telephone, with dimensions of about 40 by 80 by 20 millimeters (mm), or greater. 
   
   
     21. The device of  claim 18  wherein the housing is a “candy bar” cellular telephone with dimensions of at least about 95 by 37 by 10 mm and the antenna has dimensions of at least 35 mm by 20 mm by 0.05 micrometers. 
   
   
     22. A meander line capacitively-loaded magnetic dipole antenna comprising:
 a transformer loop having a balanced feed interface; and 
 a meander line capacitively-loaded magnetic dipole radiator connected to the transformer loop and comprising a plurality of meander line groups, each meander line group comprising a plurality of meander lines.